Cleaning and defragmentation

i was wondering one thing ...
If i use a cleaner (ccleaner, regseeker, jv16powertools, etc ...) and that for whatever reason (bug?) deletes entries in the register that should not, is there risk to change the settings of programs installed in my system? Or the only risk is of missing files? I mean, are there also programs that "interpret" deleting files, like a restoration of default values for its option?

Then, if i set automatic defragmentation (or cleaning ..) and simultaneously convert a file, is there the risk that if both programs are trying to access the same time, conversion fails?

i was wondering one thing ...
If i use a cleaner (ccleaner, regseeker, jv16powertools, etc ...) and that for whatever reason (bug?) deletes entries in the register that should not, is there risk to change the settings of programs installed in my system? Or the only risk is of missing files? I mean, are there also programs that "interpret" deleting files, like a restoration of default values for its option?

Click to expand...

If you are running Windows XP, you can go to Help and Support on your
computer. If you do a search on "registry" you will find an overview
article. Here is a partial quote from that file on XP. I don't run Vista,
but I presume there is similar info there:

"Warning

Incorrectly editing the registry may severely damage your system.
At the very least, you should back up any valued data on the computer
before making changes to the registry. If you do damage your system,
you may be able to repair the registry or restore it to the same version
you were using when you last successfully started your computer.
Otherwise, you must reinstall Windows."

Back before I had imaging software, I regularly reinstalled Windows,
often as a result of registry damage done by testing software.

I can't speak for all cleaners, but three that I use all offer the
option to to back up and restore any registry entries which they
delete.